A typical backup storage network system may include a backup server computer managing backup operations from client computers to storage node computers. The storage node computers in turn may deposit backup data to backup storage devices. These devices may be tape devices, optical disk devices or other types of devices capable of long-term data storage. The backup system may be managed by backup server software that initiates the backup process according to a schedule set by the system administrator. Each component of the backup storage network system may be connected via a storage area network, local area network, wireless network, wide area network or any other type of communication network familiar to one skilled in the relevant art. One will also appreciate that the backup storage network system components may be directly or remotely connected to one other.
The backup storage network system may permit backup and storage of data from multiple client computers to multiple storage node computers, each running a separate operating system. The backup storage devices may each be managed by separate storage node computers, which may in turn have a number of backup storage devices connected to them. In order to keep track of each backup storage device connected to a storage node, each backup storage device has at least its own serial number and unique address. This address may use a series of numbers consistent with the “bus.target.lun” format common to small computer system interface (SCSI) devices. This address may also be stored on the backup storage network server. One will appreciate that many types of address formats are possible. During a backup process, backup server software may identify and route data to the backup storage device using this address.
Occasionally, a storage node computer may reorganize the backup storage devices that it manages, causing the addresses for some of its backup storage devices to change. Reorganization of backup storage device addresses on the storage node computer may be a feature of the storage node computer's operating system, and can occur for any number of reasons known to one skilled in the relevant art. A consequence of this reorganization is that the storage node computer's internal list of addresses for its associated backup storage devices no longer matches the backup server's or backup server software's address list of backup storage devices. The storage node computers nor their associated backup storage devices do not automatically notify the backup server software of the reorganization, nor do they update the backup server software with the backup storage device address changes. The storage node computers may operate independently from the backup server and the backup server software.
The backup server may initiate a backup process according to a pre-set schedule managed by the backup server software. If this occurs after a reorganization, the server or server software will not be able to communicate with or access the backup storage devices because the backup storage devices addresses known to the backup server software will not match up to the reorganized backup storage addresses known to the storage node computers. This will cause the backup process to stall. The backup process therefore does not complete, defeating the purpose of the backup and putting data assets at risk. In addition, the system administrator may not be notified of the problem, so discovering the reason for the backup failure becomes an arduous task.
What is needed is an improvement to current storage area network systems that backup data to backup storage devices managed by storage node computers. What is needed is a way to allow storage node computers to reorganize their associated backup storage devices, while automatically and dynamically updating the backup server software and/or backup server computer of any backup storage device address changes resulting from the reorganization. What is further needed is a way to notify a system administrator when a backup process stalls or fails because of a reorganization. What is further needed is a way to resume an interrupted backup process once the problem has been identified.